Gaseous electric discharge lamp device



Feb. 5, 1935. c. BOL ET AL- 4 1,990,164

GASEOUS ELECTRIC DISCHARGE LAMP DEVICE Filed Sept. 18, 1954 c%?.1 i -4 5 "5 -5 In INVENTORS BY z.

ATTORNEY Patented Feb. 5, 1935 UNlTED STATES- a t e 1.096.164 oassons smcrmc mscmos um nsvrcs Cornelia Bol and Hendrik A. W. Klinkhamer, Eindhoven, Netherlands, auig'nors to General Electric Company, a corporation of New York Application September 1s, 19:4, Serial N... 744,487 I In Germany September 30, 1983. I

4 Claims. (01. 176-124) The present invention relates generally to gaseous electric discharge lamp devices and more particularly the invention relates to starting and operating circuits for a plurality of such devices similar to that described in co-pending application, Serial Number 645,283, filed December 1, 1932, the inventor being Hendrik A., W. Klinkhamer.

In the co-pending application an illuminating system is disclosed which comprises a plurality of gas filled electric discharge devices, each having a, thermionic electrode, and a plurality of transformers, one for each of said devices, having the primaries thereof connected in series to the terminals of a current source. The operating voltage of such devices is appreciably lower than the starting potential thereof. The voltage of the current source in such a system must be greater than the sum of the operating voltages of the various devices but need not equal the sum of the starting potentials of the devices. It is understood, of course, that the starting and operating voltages of each lamp device ismeasured between the terminals of the transformer across which the lamp device is connected rather than between the electrodes of the lamp device. As a result of the cooperative action of the thermionic electrodes and of the series-wired transformers, the potential necessary to start the lamp devices in the system is smaller than the sum of the starting potentials of the devices. When external im-v pedance consisting of ohmic resistances are used, this has the advantage that these resistances can be made smaller so that the energy which is lost therein is reduced. If, as is customary, the external impedance consists of an auto-inductance then this also canbe made smaller which results in a better performance factor. The number of lamp devices which can be started on' a certain voltage in a circuit of this type is greater than in prior circuits.

The object of the present invention is toimprove illuminating systems of the above type so that the number of lamp devices in the system which can be started on a certain voltage can be increased. Another object of the invention is to increase the efilciency of illuminating systems .of this type. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the-follo g particular description.

In' accordan with these objects the transformers in the new and novel illuminating system have such structure that they are strongly saturated after current is applied thereto and before the discharge in the lamp device connected thereto has started. A choke-coil, connected in 'series with the transformers in the system, has

such structure that it is unsaturated during this period. We have demonstrated that transform- 5 ers and a choke coil having these characteristics in this type of circuit facilitate the starting of the lamp devices in the circuit. The reason for this phenomena is probably that higher harmonics (principally the third) are present in the voltage supplied to the lamps by the transformer secondaries though we do not wish to be bound by this explanation. A choke coil having a large leakage field and capable of regulating the current within certain limits is preferred.

The invention will be readily understood from an inspection of the drawing accompanying and forming part of this specification and a perusal of the following detailed description thereof. In the drawing Fig. 1 is a schematic representation of one embodiment of the invention, and

Fig. 2 illustrates a type of choke coil useful in the circuit illustrated in Fig. 1.

Referring to Fig. 1 of the drawing the new and novel illuminating system comprises a plurality of transformers 2 the primary coils 3 of which are connected in series with each other and with the choke coil 4 across the terminals 1 of an alternating current source. To each secondary coil 5 of the transformers 2, a discharge lamp 6 is connected. Each-of these lamps is U-shaped and has a thermionic electrode 7 at each end thereof. These electrodes 7 are heated to the required high, electron emitting temperature by the discharge, although when desired, a special heater current is used to heat said electrodes 7 to such temperature.

The lamps have a gaseous atmosphere therein comprising a fixed, starting, rare gas, such as neon, at a pressure of 1 to 10 mm., and a'quantity of vaporizable materiahsuch as sodium, cadmium, caesium, magnesium mercury, rhubidium, or mixtures or amalgams thereof, the vapor of which participates in the light emission inten- 46 sively during operation of the lamp. It will be understood that the gaseous atmosphere consists of a fixed-gas or a mixture of fixed gases, or of a metal vapor or a mixture of metal vapors, when desired.

The transformers 2 are so constructed that they are strongly saturated when idle, that is before the lamps have started into operation, so that in this case we are working beyond the hump of the curve which represents the induction as a function of the current. In using the usual alloy iron as material for the transformer cores the induction is chosen over 14000 and preferably over 16000 or even 18000.

The structure of the choke coil 4 is shown in Fig. 2. On the core 8 two coil parts 9 and 10 are arranged of" which part 9 has a fixed position while part 10 is movable in a vertical direction and is hung on the balance 11 on which the counterweight 12 is fastened. The coil parts 9 and 10 are so wound that they attract each other. This attractive power and the inherent weight of the coil part 10 are equal to the counterweight 12. With a growing current strength the gap between the coil parts 9 and 10 becomes smaller'so that the leakage field becomes weaker and the self-induction becomes greater. The greater attraction between the coil parts-is here equalized by the longer lever-arm of the counterweight 12.

The choke coil 4 is so constructed that, when through the installation almost constant.

While we have shown and described and have pointed out in the annexed claims certain novel features of the invention, it-will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated andinitsuseandoperationmaybemadeby them skilled in the art without departing from the broad spirit and scope'of the invention, for example, auto-transformers are used in place of the' type of transformers 2 shown and described.

What we claim as new and desire to. secure by Letters Patent of the United States is:-

1. An illuminating system comprising in combination a plurality of gaseous electric discharge lamp devices, a plurality of transformers therefor, said transformers being connected in series across the terminals of an alternating current source, each of said devices being connected across the terminals of one of said transformers. a choke coil connected in series with said transformers.

said transformers being saturated and said choke coil being unsaturated before the discharge has started in said lamps whereby the starting of said lamps is facilitated.

2. An illuminating system comprising in com-v bination a plurality of gaseous electric discharge lamp devices, a plurality of transformers therefor, said transformers being connected in series across the terminals of an alternating current source, each of said devices being connected across the terminals of one of said transformers and comprising a thermionic electrode and a gaseous atmosphere comprising a metal vapor, a choke coil connected in serieswith said transformers,

said transformers being saturated and said choke v coil being unsaturated before the discharge has started in said lamps whereby the starting of- .said lamps is facilitated.

3. An illuminating system comprising in combination a plurality. of, gaseous electric discharge lamp devices, a plurality of transformers therefor, said transformers being connected in series across the terminals of an alternating current source, each of said devices being connected across the terminals of one of'said transformers and comprising a thermionic electrode and a gaseous atmosphere comprising a fixed gas anda metal vapor, a choke coil connected in series with said transformers, said transformers being saturated and said choke 0011 being unsaturated before the discharge has started in said lamps whereby the starting of said lamps is facilitated.

4. Anilluminating system comprising in combination a plurality of gaseous electric discharge lamp devices, a plurality of transformers therefor, said transformers being connected in series across the terminals of an alternating current source, each of said devices being connected across the terminals of one of said transformers and comprising a thermionic electrode and a gaseous atmosphere comprising a fixed gas and sodium, a choke coil connected in series with said transformers, said transformers being saturated and said choke coil being unsaturated before the discharge has started in said lampswhereby the starting of said lamps is facilitated.

coRNEms non. HENDRIX A. w. 

